1. Field of the Invention
The present invention generally relates to an induction system for motorcycle. More specifically, the present invention relates to an air silencer and filter arrangement for a motorcycle engine.
2. Description of the Related Art
In a motorcycle having a V-type engine, the engine is generally mounted on the frame with the crankshaft oriented transversely with respect to the longitudinal direction of the motorcycle. A space is therefore defined between the fore and aft cylinders and one or more carburetors are disposed in this space. The cylinders are formed with intake ports at the sides facing toward the space so as to be connected with the carburetor or carburetors in the space.
In this type of motorcycle, an air filter is typically disposed behind the engine so that intake passages extend from the air filter, around the aft cylinder, and to the space between the cylinders. Such an intake system is difficult to manufacture because the intake passages are relatively long.
Other induction system designs have included an air chamber and filter disposed above the engine. However, because the fuel tank is typically disposed directly above the engine of a motorcycle, there is little space between the top of the engine and the fuel tank for an air chamber and air filter assembly.
Japanese Patent No. 2857926 discloses a motorcycle having an induction system comprising an air box disposed rearward from the engine in which two air filters are disposed. Each air filter is fed with a different intake pipe. The intake pipes open through an upper surface of the air box. One filter is disposed adjacent an upper surface of the air box and a smaller is disposed below the first filter. This design, however, is difficult to use with a V-type engine having the throttle bodies disposed in the space between the cylinders.